On today's BradCast: It's been 29 years since NASA's chief scientist, Dr. James Hansen, offered landmark testimony to the U.S. Senate in June of 1988, explaining that scientists had determined with 99% certainty, as the New York Times reported it at the time, that record atmospheric warming since the 1950s "was not a natural variation but was caused by a buildup of carbon dioxide and other artificial gases in the atmosphere." [Audio link to show follows below.]

Of note in the Times coverage at the time --- headlined "Global Warming Has Begun, Expert Tells Senate" --- there was nobody quoted from the fossil fuel industry offering denial to the basic scientific facts about which Hansen and others testified that day, based on temperature records going back (at the time) 130 years, and finding that the first five months of that year had been the hottest on record. (The record temperatures that year don't even rate among the top 20 anymore.)

"It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here," Hansen told the paper after his 1988 testimony. "Global warming has reached a level such that we can ascribe with a high degree of confidence a cause and effect relationship between the greenhouse effect and observed warming,'' he testified to the Senators. ''It is already happening now.''

The panel of scientists warned that "If the current pace of the buildup of these gases continues, the effect is likely to be a warming of 3 to 9 degrees Fahrenheit from the year 2025 to 2050." They were pretty much exactly on target, so far, with those projections. Then Senator Timothy E. Wirth (D-CO), chair of the Committee, responded: "'As I read it, the scientific evidence is compelling: the global climate is changing as the earth's atmosphere gets warmer. Now, the Congress must begin to consider how we are going to slow or halt that warming trend and how we are going to cope with the changes that may already be inevitable."

In the 29 years since --- particularly in the seven years since the Supreme Court's Citizen United opinion unleashed unlimited fossil fuel industry funds into our electoral process --- Republicans (and some Democrats) have instead figured out how to "cope with the changes" by denying they exist at all, or pretending there is uncertainty about who is responsible for it.

But the science is very clear, even more now than than. (And it was even clear some 30 years prior to Hansen's 1988 testimony, as a clip from a 1958 television program, dug up by Desi Doyen and played in part on today's show, makes evident.) And yet, the President of the United States and his top lieutenants --- among them EPA Administrator Scott Pruitt and Energy Secretary Rick Perry --- have been taking to the airwaves of late to confuse the public with blatant misinformation to distract from the point that man is responsible for all of Earth's warming recorded since the 1950s.

Marking the 29th anniversary of Hansen's testimony, naturalist and author Tony Russell penned a very simple, very clear explanation --- "Global Warming in a Nutshell" --- of the very simple science and math behind global warming, how we know that man is responsible for the 48% increase of heat-trapping CO2 over the past 60 years (CO2 emitted by the burning of fossil fuels lacks a specific carbon isotope, so we can actually measure it!), and what we must do about it...and quickly. He joins us today to discuss that article, and the reasons he wrote it. "I have 9 grandchildren," he tells me, "so they are very much on my mind."

"In some ways, I'm starting to see our situation as desperate," he warns, explaining how it is that we know that disinformation from folks like Pruitt and Perry is simply, and demonstrably, wrong. "When you have warming in the pipeline, with CO2 hanging in the atmosphere that's going to continue to re-radiate heat for tens of thousands of years, and we keep adding new carbon dioxide to the mix, there's no way to stop it. We're loosing a runaway train."

Noting that natural sources, such as oceans and forests, have been able (at least up until recently) to absorb some 50% of the carbon we release, Russell explains: "If you want to stop adding to the CO2 in the atmosphere, then humans have to cut their emissions by 50% from current levels. The figures you see are usually on the order of cutting emissions by 20% by, say, the year 2025. Every year that you hold it at 20%, then 30% will go into the atmosphere. CO2 levels will keep on climbing, more long term warming will be locked in. It really is that simple."

We've covered climate quite a bit over the years on The BradCast and, of course, on our Green News Report. But sometimes it's important to go back to the basics on how stark the science and the reality of our dire situation now is.

On the same topic, speaking of U.S. Senate testimony that's been too-much overlooked, as Dr. Joe Romm at Climate Progress notes this week, Sen. Al Franken (D) recently "set climate deniers' last strawman on fire" during an exchange last week with Sec. Perry, when the Minnesota Senator pointed out that even the Koch Brothers own climate scientist Richard Muller recently conceded that all of the recent warming in the atmosphere was due to our burning of fossil fuels. We play the remarkable exchange today in full.

Also today: Wildfires break out across the West (for some reason); Senate Republicans are having a difficult time getting to 50 votes on their legislation to repeal ObamaCare (at least without Democrats helping); And our small, bitter President unleashes an ugly, bitter, embarrassing and mostly just sadassault against journalist Mika Brzezinski, from atop his bully pulpit (pun intended)...

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“Senate Republicans are having a difficult time getting to 50 votes on their legislation to repeal ObamaCare....”

Difficult enough to have given up and gone home without a vote — let all their constituents make sure to lobby them very, very thoroughly on this matter during the recess, lest they somehow remain blithely unaware of public opinion, and think they’ll be safe for re-election if they vote for such a bill.